1989 NC30 Project / rebuild

[RickDonoghue]

Carbs have been dropped off for ultrasonic cleaning and the front calipers are nearly finished.

Interestingly I took the bike off it's center stand for the first time this weekend and the standard spring on the BMW S1000RR rear shock is far too soft as people have mentioned. I can't quite understand how since the honda is lighter than the BMW but I guess it could be down to the geometry / weight distribution of the bike, if that's the correct term... I should've listened!!
I have got another custom spring for it but the diameter of the spring looks far too big since the standard BMW spring is only about half a centimeter away from fowling the swingarm. Also the lower linkages are even closer to fowling the exhaust downpipes.

If I adjust the BMW shock by tightening the ring around the diameter will this not make it much stiffer? I'm really not convinced that this custom spring I had from Springcoil will fit...

[bikemonkey]

It's to do with the rising rate of the linkages.

You either need a much heavier spring, or get Rick O's HRC replica linkages

[TURK122]

It's to do with the rising rate of the linkages.

You either need a much heavier spring, or get Rick O's HRC replica linkages

Sorry to thread jack
Are you saying that the standard BMW shock doesn't need the spring changing if the Rick Olivier HRC linkages is used?

Thanks
TURK

[RickDonoghue]

Now I've spent a while getting this bike built back up... whats the easiest way to get the shock back out? does the subframe need taking off again and the undertray ?

[bikemonkey]

No spring change needed if you have the linkage, correct.

Easiest way to get the shock out is get the bike on a stand that isn't compressing the rear suspension, support the weight of the swingarm (wheel removed) and go from there.

It can be fiddly to remove the shock, just take care as it's very easy to chip the spring coating/paint

[RickDonoghue]

I've not managed to get much done this weekend, again! I've rebuilt the front calipers and fitted them along with the brake lines. I did have a bit of a go at bleeding the system but no luck... I think I need to consult the haynes manual! I bled the master cylinder by slightly loosening the bolt through the lines then pulling the brake lever in and tightening the bolt after this, then releasing the lever. this was repeated several times and I then moved onto the bleeding nipples on the calipers however still no pressure building up... Why are these things never straight forward!!!



Could anyone give me some tips please?

Thanks

[Dynamohum]

That method does work eventually a lot of air gets trapped at the top near mastercylinder just keep working away as your doing i even removed lever and used a a screwdriver on plunger on mastercylinder to see if it gave a longer stroke although it can take time took me best part of an hour and half to get my rvf fronts done a syringe used to draw fluid through or a vacuam bleeder speeds the process to minutes .

[newtothis]

Are you sure there's no pressure? I rebuilt mine recently and the new seals were pulling the pistons back into the calipers when the lever was released. Pumping the brakes did cause the lever to firm up a bit but it promptly went back to a lot of lost motion. After a ride it was fine and the brake action is now immediate and no hint of sponginess.

[RickDonoghue]

After much consideration I've decided to scrap my current front brake calipers anyway! After all the hassle with powdercoating and new seals etc. I decided they aren't right due to small amounts of the powdercoating sneaking into the bores I had to quite aggressively remove it and I'm not convinced that I haven't damaged the bores...

I've been onto Rick.O and have decided to upgrade them to CBR900RR brakes with the modified mounting brackets. The ones I've purchased also have a nice silver finish which I'm happy about as I wasn't keen on the current grey ones (grey with grey forks). All the new seals and and the brakes themselves should be delivered this week and I will hopefully install them this weekend.

I managed to get my new radiators on this week (from Scott Jelleyman) and they seem to be ok. A little bit fiddly to fit but the mounts are pretty flexible and they drill the fan mount holes in a kind of oval shape so you can position things where you desire. Another slight issue is that I believe my exhaust is an aftermarket one therefore it's a bit chunkier... The radiator is also a little deeper which doesn't leave too much space between them for the fan but I've just about managed. due to this the powdercoated fan bracket may be slightly touching the front exhaust headers...

They look smart anyway...

[RickDonoghue]

CBR900 calipers to be rebuilt and put on the bike this week!



17 years old these calipers, just a de-grease and polish, Honda build quality again...